package Linkedlist;

import jdk.jshell.spi.SPIResolutionException;

public class MyLinkedlist implements Ilist{
    //ListNode类
    static class ListNode{
        public int val;
        public ListNode next;
        public ListNode prev;
        public ListNode(int val) {
            this.val = val;
        }
    }

    public ListNode last;//尾节点
    public ListNode head;//头节点

    @Override
    public void addFirst(int data) {
        ListNode node=new ListNode(data);
        if(head==null){
            head=node;
            last=node;
        }
        else{
            node.next=head;
            head.prev=node;
            head=node;
        }
    }

    @Override
    public void addLast(int data) {
        ListNode node=new ListNode(data);
        if(head==null){
            head=node;
            last=node;
        }else{
            last.next=node;
            node.prev=last;
            last=node;
        }
    }

    @Override
    public void addIndex(int index, int data) {
        int len=size();
        if(index<0 || index>len){
            System.out.println("下标越界："+index);
            return;
        }

        if(index==0){
            addFirst(data);
            return;
        }
        if(index==len){
            addLast(data);
            return;
        }

        ListNode node=new ListNode(data);
        ListNode cur=findIndex(index);
        node.next=cur;
        node.prev=cur.prev;
        cur.prev.next=node;
        cur.prev=node;
    }

    private ListNode findIndex(int index){
        ListNode cur=head;
        while(index!=0){
            index--;
            cur=cur.next;
        }
        return cur;
    }


    @Override
    public void remove(int key) {
        ListNode cur = head;
        while (cur != null) {
            if (cur.val==key){
                if(cur==head){
                    head=head.next;
                    if(head==null){
                        last=null;
                        return;
                    }
                    head.prev=null;
                }else {
                    if (cur == last) {
                        last = last.prev;
                        last.next = null;
                        return;
                    } else {
                        cur.prev.next = cur.next;
                        cur.next.prev = cur.prev;
                    }
                }
                return;
            }else{
                cur=cur.next;
            }
        }
    }
    @Override
    public void removeAllKey(int key) {
        ListNode cur = head;
        while (cur != null) {
            if (cur.val==key){
                if(cur==head){
                    head=head.next;
                    if(head==null){
                        last=null;
                        return;
                    }
                    head.prev=null;
                }else {
                    if (cur == last) {
                        last = last.prev;
                        last.next = null;
                        return;
                    } else {
                        cur.prev.next = cur.next;
                        cur.next.prev = cur.prev;
                    }
                }
            }
            cur=cur.next;
        }
    }

    @Override
    public Boolean contains(int key) {
        ListNode cur=head;

        while(cur!=null){
            if(cur.val==key){
                return true;
            }
            cur=cur.next;
        }
        return false;
    }

    @Override
    public int size() {
        ListNode cur=head;
        int cout=0;
        while(cur!=null){
            cout++;
            cur=cur.next;
        }
        return cout;
    }

    @Override
    public void clear() {
        ListNode cur=head;
        while(cur!=null){
            ListNode curN=cur.next;
            cur.prev=null;
            cur.next=null;
            curN=cur;
        }
        head=null;
        last=null;
    }

    @Override
    public void display() {
        ListNode cur=head;
        while(cur!=null){
            System.out.println(cur.val+" ");
            cur=cur.next;
        }
    }
}
